TM-9-2350-261-34 Direct and General Maintenance Manual M113A2 M577A2 M1064 M1068 M1059 M901A1 Download
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TM 9-2350-261-34 PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS), INCLUDING LUBRICATION INSTRUCTIONS — Continued 0014 00 2. WELDING IN ST RUC TION S. Welding safety precautions and welding procedures are given in the f ollow ing steps. Special instructions are covered in the task. a. SAFETY PRECAUTIONS. 1) Wear clothing such as leather or heavy denim. Do not wear clothing with loose pockets, trouser cuffs, or short or rolled up sleeves. 2) Do not expose bare skin to welding arc. 3) Do not look directly at welding arc unless you are wearing a welding hood. 4) Wear flash goggles or tinted safety glasses (No. 2) in welding area. 5) Disconnect power source before changing parts or making equipment repairs. 6) Do not touch mechanism or any part of the electrode. 7) Make sure welding area has plenty of fresh air without being drafty. Remove all toxic and combustible materials. 8) Make sure all electrical and gas connections are tight. 9) Do not touch any metal in welding area with bare hands. Aluminum does not change color when hot. 10) Do not weld in the fuel compartment where sealing compound has been applied. 11) Use a welding screen to protect personnel from arc flash. b. GENERAL WELDING PROCEDURES. 1) B ASIC W ELD ING R EPA IRS. Repairs are m ade on 50 83 alu minum allo y using the M IG (Metal-Inert-G welding method. 2) CONTRACTION AND EXPANSION. Aluminum welds contract about 6 percent in volume when they become solid. Welding at slow speed may cause too much heating of the area around the weld. This will cause the metal to expand too much or melt. It will then cause cracking upon cooling. 3) FILLER WIRE. Always use clean wire. Filler wire polluted by grease, oil, dust, or shop fumes causes porous welds. After welding, cover wire to prevent pollution. Store covered wire in warm, dry place. 0014 00-9 4) CLEANING OF WELDED SURFACES. Remove oxides, grease, oil films, paint, and all foreign matter from joint before welding. Wipe edges of joint with a clean cloth dipped in cleaning compound and let dry before welding. Sand with disk sander or brush surface with clean stainless steel wire brush to remove oxide. Clean up weld area and touch up paint all bare metal. See TM 43-0139. 5) FIT-UP AND TACKING. Good joint fit-up makes welding easier, saves filler wire and gas, and helps get higher quality welds. You must tack weld to hold the joint members in place if you don’t have jigs. Tack welds should be small, neat, and placed right to keep parts lined up before and during welding. 6) WELDING UNEQUAL SECTIONS. When welding unequal sections, direct arc against heavier piece to fuse the two edges evenly. Watch weld pool edge rather than arc to ensure weld pool edges fuse right. 7) MULTI-PASS WELDING. Make sure edges of weld pool fuse right. Watch weld pool rather than arc. Any oscillating of weaving motion should be slight, smooth, and slow. Brush material with clean stainless steel wire brush after each pass. On small weldments, lower amperage slightly after each pass if welding members become too hot.